Rather fittingly, one of the greatest mystery writers in history has left us with one last mystery to solve. Edgar Allan Poe was found wandering the streets of Baltimore on October 3, 1849, barely conscious and wearing cheap, ill-fitting clothes that no one recognized as belonging to him. He was taken to a nearby hospital, where he spent the next few days delirious and confused, unable to tell his caretakers what happened to him. During this time, he is said to have repeatedly shouted out the name "Reynolds!" though no one knows what this means. On October 7, Poe spoke his final words—"Lord help my poor soul!"—and passed away. No autopsy was performed on his body, and the cause of Poe's death is still hotly debated. Here are a few of the most popular theories:

1. Alcoholism

Newspapers at the time reported his cause of death as "congestion of the brain," which was a phrase often used as a euphemism for disreputable deaths such as alcoholism. Poe struggled with his relationship to alcohol throughout his life, occasionally over-indulging and then swearing off the drink for long stretches of time. Less than two months before his death, Poe was initiated into the Sons of Temperance in Richmond, an anti-alcohol organization. Despite his pledge of temperance, it's entirely possible that Poe could have relapsed and given himself over to drink one final time.

2. Beating

In 1867 one biographer, E. Oakes Smith, reported that Poe had been beaten up by a "ruffian," as revenge for offending a particular woman. Other theories combine this one with the notion of alcoholism above, saying that he'd given in to peer pressure and joined a few friends for a drink. He became extremely drunk—some say after only a single glass of champagne—and was robbed and beaten while wandering the streets of Baltimore in this vulnerable state.

3. Drugs

A rumor has risen up after Poe's death that the poet was addicted to the popular drug opium. This theory is often supported with evidence from Poe's writings, as several of his stories explore in great detail the thoughts and experiences of narrators who indulge in the drug. There is little evidence to suggest that Poe actually was a serious user of opium during his lifetime, although one of his letters does allude to an incident in which he attempted suicide by overdosing on laudanum—a popular medicine at the time, consisting of opium and alcohol. Could Poe have recreated that earlier suicide attempt later in his life?

A variation on this theory is that Poe did not willingly take drugs himself, but that he was drugged by somebody else. When the rumors began circulating that he had died from alcoholism, Poe's honorary brothers in the Sons of Temperance organization responded with the following statement: "We of the temperance order to which he belonged exerted ourselves to get at the facts, and the consensus of opinion was that he had not been drinking, but had been drugged."

4. Cooping

"Cooping" refers to a type of election fraud that was somewhat common during the 19th century. Cooping gangs, on the payroll of a particular politician, would grab random people off the street and force them to vote, sometimes several times over, for that candidate. The victim would be "cooped up" in a small room, threatened, and plied with drugs and alcohol until they complied. Sometimes they were dressed in different clothing and disguises and brought around to multiple polling stations. If they did not cooperate, they would be beaten or even killed. The fact that Poe was found by Walker near the Ryan's Fourth Ward polling station on an election day adds credence to this theory. It would also explain why he seems to have been wearing clothes that didn't belong to him, and why he was seemingly under the influence of drugs or alcohol, despite the assurances from this close friends that such things would be out of character.

5. Carbon Monoxide Poisoning

A public health researcher named Albert Donnay presented a theory in 1999 that Poe had died from carbon monoxide poisoning. The coal gas that was used for indoor lighting during the 19th century could have given him frequent exposure to this dangerous chemical. Donnay suggested that chronic carbon monoxide poisoning could account for some of Poe's unexplained traits like his unusually low tolerance for alcohol, recurring fatigue, and hypersensitivity to lights, sound, tastes, and touch. Donnay took clippings of Poe's hair to test them for evidence of exposure to coal gas, but the results were inconclusive.

6. Rabies

When given a list of Poe's symptoms in 1996, Dr. Michael Benitez concluded that the man had clearly died of rabies. This virus was fairly common in the 19th century, and it was not unusual to come across the case of a person who had contracted rabies after being bitten by a dog. Symptoms of the disease include confusion, delirium, and hallucinations, all of which match with descriptions of Poe during his final days. He died within 4 days of showing symptoms, a time frame that matches up with rabies. However, the key element of this theory seems to have been based on a misunderstanding: some reports of Poe's death suggest that he showed the most recognizable symptom of rabies—hydrophobia, or the fear of water and inability to drink. But the notes of the doctor who attend him state clearly that Poe was able to drink water without issue. Either way, it is impossible to know for sure whether Poe had rabies without DNA evidence.

These are just a few of the many fascinating theories that are out there. Which explanation for Edgar Allan Poe's death do you believe in? Do you have a theory that wasn't mentioned here? Share your thoughts in the comments!